Water-well drilling

Description

The contracting entity is tendering to establish a multi-supplier framework for the provision of appropriately qualified and experienced groundwater drilling Contractors to provide expert groundwater drilling services. The scope comprises 3 elements: 1) Trial wells; 2) Production wells; 3) Testing. As per tender documents. The contracting entity is tendering to establish a multi-supplier framework for the provision of appropriately qualified and experienced groundwater drilling Contractors to provide expert groundwater drilling services. The scope comprises 3 elements: 1) Trial wells: drilling, well development and completion of groundwater exploration trial wells in various soil conditions, for the purposes of determining the suitability of a site for groundwater supply for the required well yield and groundwater quality. Borehole diameters shall be up to 200 mm internal diameter. The Contractor shall provide and install all required materials for the trial well development and completion. The well shall be developed with compressed air, until the discharge water is clear. The Contractor may be required to abandon and backfill wells, as directed by the employer’s representative; 2) Production wells: drilling, well development and completion of water supply production wells in various soil conditions. The depths of the pump chamber casing and the well are dependent on the soil conditions. The Contractor shall provide and install all required materials for the production well development and completion, including a sealed pump chamber casing. The well shall be developed with compressed air, until the discharge water is clear. The Contractor may be required to remove material in existing wells to facilitate the subsequent re-fitting of the well to achieve a quality of finish at the level of that described in EPA Note No.14; 3) Testing: post-drilling testing, water sampling and monitoring, and surveying of existing and newly drilled boreholes/wells. Pumping tests required are step tests, constant rate tests, and recovery tests. Water quality sampling and testing (number of specified suites of parameters) is required. The scope also includes camera surveys and sampling and monitoring, as directed by the employer’s representative.